Hi,You can pretty use whatever ribbon you would like. I let my cake crust up over night and apply the ribbon the next day with clear piping gel. I usally put a zig zag line the ribbon and then apply and if you see any place that might need a bit of extra gel I do just a dot and then smooth it to the cake. Hope this helps...

polyeurothane (sp?)works better than polyester. I apply the ribbon the next day, at the venue, after the icing has crusted. I do not deliver already assembed, so the cake is assembled, then ribbon applied. I use one dot of BC to glue the two ends together in the back.

Indydebi is right (of course). Polyester or any fabric-type ribbon tends to soak up grease from icing with any type of grease. I tried it on a cake made from a chocolate fudge icing (cocoa, powdered sugar, butter, water, vanilla). The icing had already crusted, and I tried to protect the ribbon with waxed paper behind it (although I hadn't yet learned about ironing it on), but it very quickly soaked up grease from the edges where it touched the cake and within an hour was completely soaked through. There is a picture of it in my photos. Some people don't mind as long as it soaks in uniformly, but it ends up looking wet to me. There are a variety of ways to prevent that, though. Waxy or plastic ribbons (they are often marked "weather-resistant") can be used. I've heard you can iron waxed paper into the back of polyester ribbon, but again even just edges touching the cake can soak up the grease. You may have to test a piece of your ribbon before applying it to the cake. Good luck!